As many here have done, I purchased an Antelope Liveclock and found it an improvement over internal RedNet and Mutec clocks. I was an external clock newbie so I purchased the Liveclock without any expectations. Given the positive outcome, I became interested in what a 10M clock could do. I know there is no concensus in regards to 10M. On the one hand you have testimony from some studio producers saying they can't live without it. On the other hand you have folks saying it makes no difference what so ever and it might as well be an expensive paper weight. Though I had interest, the expense was prohibitive. The Antelope 10M is over $5K, the Stanford Perf 10 is $3500 and the upcoming Mutec Ref 10 has been rumored to be 3000 Euros. All over my comfort zone financially. A little additional searching brought forth a potential alternative - Cybershaft of Japan. A few US based posters have had positive results (mostly feeding esoteric players) but the sample size is small with majority of users in Japan.
I initially contacted Hasegawa-san and inquired about the various 10M options (He sells both OCXO and Rubidium and even a unit that contains both). He asked what I was going to use the clock with and my musical preferences. He first confirmed that his clocks are compatible with the Antelope Liveclock and then mentioned that his recommendation would be the OCXO Premium for my listening habits (weighted more toward Classical side of things). Payment for clock and 50-ohm bnc cable was via Paypal and unit was shipped out via EMS in a few days. Total charge for clock, cable and shipping with exchange rate was $1K.
Unit arrived yesterday. The OCXO Premium has some real heft to it. It's easily 2x-3x times the weight of the Liveclock. The Cybershaft also has a better overall build quality than the Antelope. As mentioned in prior posts, the unit comes with certificate of calibration that shows individual unit test results with some graphs.
The Cybershaft was connected to the Antelope and the Atomic Clock connection of the Liveclock instantly lit up. The Atomic indicator also was indicated in the Antelope Software. I let the unit warm up for for the afternoon and early evening and started listening in earnest around 8PM. I wrapped around 2AM.
Overall impression is that Cybershaft into Liveclock is preferable to Liveclock on its own. Imaging is more solid and individual musical lines in a complex orchestral piece seem easier to distinguish/follow. One of my "go to" evaluation recordings is Debussy's three nocturnes conducted by Haitink and the Concertgebouw on Philips. The nocturnes is awash in orchestra color with winds (flutes, piccolo, oboes, clarinets, bassoons), horns (trumpets, trombones, tuba), percussion (timpani, cymbals,snare), two harps and a wordless female choir. The instrumental separation just seemed more prominent with the Cybershaft in the mix. This opinion remained consistant with just about all other orchestral pieces I played as well.
Any downsides? Well I will say that when I switched genres and listened to some down and dirty garage rock the Cybershaft seemed to have perhaps a little less bite than the Liveclock. The Cybershaft provided the extra bit of clarity/resolution but in some songs I'm not sure if that is the best thing. A good example is when I first got a Koetsu cartridge and listened to the Stooges "Fun House". The Stooges IMO work best on a primal level when they are bashing you over the head with sonic sledgehammers. Instrumental nuance and line separation is not the game here. A thick and hard hitting wall of sound that kicks you in the gut is. What is interesting is that Hasegawa-san recommended a Rubidium clock if my primary musical interest was rock.
If you already own a Liveclock and listen to a lot of Classical/Jazz and acoustic music I would recommend the Cybershaft Premium OCXO as a nice addition. I think from a musical enjoyment perspective it provides value worth the asking price.
How does it compare to other clock alternatives? Unfortunately, I can provide no guidance there as I have not heard others in my system. Therefore I can only stick with my direct personal experience which has been that (a) Antelope >Internal Mutec (and RedNet) and (b) Cybershaft/Antelope > Antelope by itself. At $1K I'm not presuming it is the bestest clock in the whole world. What does seem rather unique about the Cybershaft is that via it's direct sales model it seems to serve a pricing niche well below most others. As always, opinions made are mine alone via 50 year old ears and my setup/room. YMMV.